Author: Chenguang 　Audiovisual Frontline

"Selling big buns" originated in the late Qing Dynasty and the early Republic of China. In order to attract diners, Guangzhou's teahouses created a chicken ball big bun with rich fillings, such as chicken, pork, bamboo shoots, etc., and the shape is naturally much larger than ordinary buns. , so it is called "big bag". If you describe today's products, it means "powerful".

At the just-concluded Guangzhou Headphone Show, the author found that many manufacturers have launched more than 10,000 earplugs, headphones, amps, decoders and other products at any time. Many friends who want to get started are intimidated by this amazing price. The author also received requests from friends around me, saying that I want to combine a set of speakers with a price of several thousand yuan. It does not need to be too complicated. I may listen to music through my mobile phone and computer, or connect to the TV in the living room, and I will be alone at night. You can also use headphones for watching movies. At this time, a set of decoding amp preamp + active speaker system + headphones can meet their needs.

In fact, such a combination is exactly what many young people need, so an all-in-one decoding preamplifier with reasonable price and excellent quality is particularly important. However, products with so many functions are often concentrated, either the price exceeds the budget, or the sound is not guaranteed. In fact, the machine for this evaluation has been in the audition room of this magazine for a while. I used it when I tested the Starke A7-2 dual-channel power amplifier before. The author recently participated in the Jinchi Hi-Fi Carnival. When matched with different combinations, this all-in-one computer entered our field of vision again. It's Century Gray's 9i-90SA Lark.

The backbone of domestic brands

Speaking of CEN GRAND, many enthusiasts may already have a certain understanding of it. CEN GRAND has been committed to the research and development of high-end digital media equipment since its establishment. It was founded by domestic senior audio designers. Relying on strong research and development strength and technical accumulation, it has integrated high-end audio technology with cutting-edge video technology to develop a series of high-performance products. Digital audio and video products. In 2010, CEN GRAND launched the 5i series of Hi-Fi audio and video players with the original audio independent dual clock + hardware DSP architecture, which established CEN GRAND's market position with outstanding performance advantages. Today's CEN GRAND has many products, covering traditional Hi-Fi and cutting-edge video high-definition fields. At present, CEN GRAND's product line includes high-end audio decoder series, Hi-Fi digital player series, Hi-Fi Blu-ray player series , Hi-Fi amplifier series, etc. Relying on profound technical background and rigorous and meticulous product concept, CEN GRAND has gradually grown into the backbone of the industry and a well-known brand in a very short period of time.

Home Video Center

The volume of the CEN GRAND 9i-90SA decoding and amp preamplifier is not large, only half the size of the standard chassis, which is very suitable for placement on desktops, TV cabinets and other places. The left side of the front panel is a medium-sized blue LED screen, and the bottom is a row of buttons. The functions of power switch, input selection, setting, mode selection, mute and other functions are all set through this row of buttons. The middle is 6.35mm and balanced headphone jack. is the volume knob. The interface on the back is also quite rich, providing a set of optical, coaxial, AES/EBU and USB inputs, while the analog input provides a set of RCA and XLR, and the output provides a set of RCA and XLR, so the lark can It can easily connect various digital and analog audio sources, and can also easily connect back-end devices such as active speakers and headphones to become the control center of home audio and video.

Unique circuit design

The basic structure of the 9i-90SA decoding headphone amplifier is WM8805 + dual AK4495SEQ + discrete device analog output circuit. The receiver chip of the digital part is WM8805, and the lowest DIR of jitter is less than 50ps, which is quite excellent. The decoding chip is dual AK4495SEQ, and the dual mono channels work independently. The highest supported format is DSD128 and PCM384. It provides four filter modes and provides standard fully balanced output. The USB AUDIO part adopts the second generation XU208 of XMOS, which doubles the performance of the previous generation.

The clock is also quite attentive, and a low-jitter clock system is independently designed. In addition, an autonomous algorithm, low jitter CPLD (additive RMS jitter is an order of magnitude lower than FPGA) is used to manage the local audio clock system, and advanced source synchronization technology and de-jitter shaping technology are used to reshape the XMOS output waveform. , which can further eliminate the additive jitter caused by the XMOS pins.

The analog part uses discrete device output, and the volume control uses a potentiometer to control the high-performance electronic volume PGA4311 chip, so the damping feel of the volume knob is very good, and there is no general digital volume that requires a few turns to adjust the volume, and the accuracy of the PGA4311 chip is higher than that of using four. The precision of the balanced amplifier circuit controlled by the potentiometer is 1000 times higher. The headphone amp is a fully balanced structure, with 6.35 unbalanced and 4-pin XLR balanced output interfaces, and there are four connection methods: standard, balanced, virtual ground, and parallel. The four connection methods provide a wider range of headphone adaptation. Whether it is high resistance or low resistance, the 9i-90SA can do it.

In addition, because the USB input of 9i-90SA adopts the latest XMOS solution, it needs to download the latest driver from the official website to install, and needs to clean up some old drivers in the system to successfully install, so players need to pay special attention. In addition, the official download link also attaches the installation file and DSD plug-in of the latest version of the foobar player, and attaches a manual for the use and setting, which is very careful.

Sound performance far beyond its worth

The author first connected the Sennheiser HD800 to the balanced headphone output interface and used the Nano Platinum Star headphone cable from the cable world. When the symphony is played in the BTL balanced form, the sound is full and heavy, and the scene is grand, which reflects the strength of Senhai headphones. At this time, the high frequency is delicate and not sharp, and it looks comfortable; when playing the human voice, it looks very comfortable, there is no sense of oppression, and the tail sound of the human voice is almost No glitches are heard, the tail is short and round, and the sound is well imaged, detailed and balanced, and there is no lack of realism. Immediately after switching to the Active G virtual ground output, when playing symphony, the sound is full, the low frequency is mixed, the overall balance is acceptable, the overtone is stronger, and the vocal performance is also very good. Switching to Parallel output, for HD800, 9i-90SA will be a bit difficult, replaced Beyerdynamic DT990, Parallel parallel output and Normal output, all can push DT990 well.

The author summarizes the matching methods of the following methods. The BTL parallel method can have a strong driving force, and it will have a good driving force for high-impedance headphones; while the Active G virtual ground output, the overtone is quite obvious, and it will be good to listen to human voices. Performance; Parallel output is quite good for medium impedance headphones, and the sound field is also very stable; while Normal output is the method of choice for low-impedance headphones and earplugs. It should be noted that the above four methods can only be implemented when the digital input and balanced input are used, while the BTL method and Active G cannot be used when the analog RCA input is used. When the headphone end is unbalanced, BTL and Active G cannot be used, in fact, it is the normal connection.

Then connect to the active monitor speaker system of similar price to 9i-90SA for trial listening. When replaying vocals, the sound is round, full and natural, the details are clear, and the vocal performance is full of charm. The connection between the high, middle and low bass is very smooth, especially the audition clip of the piano solo, which I especially like. Listening to the cello and piano sonatas, the low frequencies of the two instruments are very deep, and the 9i-90SA can still easily deconstruct the musical lines and low frequency extensions of the two different instruments in the bass region, and faithfully reproduce the music in this piece. Due to the sense of scale and the stable and wide bottom structure, it presents the shape of a piano and a cello. Obviously, whether it is strings or pianos, the 9i-90SA can show a very clear image of the outline and the graininess of the keys. In terms of sound quality, it can take into account the extremely dense and smooth texture and the balanced three frequency bands of high, medium and low. Distribution.

In the end, the author specially listened to the USB input, and played the 24bit/384kHz and DSD128 high-format files purchased by the author through the Foobar2000 of the Windows system. No matter the resolution, detail, density and dynamics, the music of 16bit/44.1kHz has a general leap in quality. , the amount of information is even more abundant to blow your face! At this time, the author switches by selecting 4 different digital filters. Slow roll-off will have more high-frequency attenuation, so the sound is more warm, while fast roll-off high frequency is relatively sharp, suitable for details and analysis. Powerful friend choice.

It should be noted that when the 9i-90SA is used as a preamp, when the XLR input is used, both the XLR output and the RCA output have signal output, while the RCA input only has the RCA signal output, and the XLR output has no signal output. When the 9i-90SA is used as a preamp or decoder output, it is recommended to disconnect the headphones on the front panel to ensure the best performance of the sound.

Summarize

This machine can be said to be the center of living room and desktop entertainment. It integrates preamp, decoding, and amp. It is very rich in functions, and there are quite a few options for users to choose from in terms of settings. The author found this product online, the price is quite attractive, you can have a "big bag" product for more than 3,000 yuan, and the quality is quite guaranteed. When the author listened to the 9i-90SA, I compared a domestic pre-production product with a level of 10,000 yuan on the spot, and the 9i-90SA actually won. Its sound performance is very valuable! Such "big bag" products, friends who need to buy entry-level audio or headphone systems, how can they miss it?